Collagen-mediated adhesion in PC3 cells was inhibited by 5-O-caffeoylquinic acid. PC3 cells were pretreated (3 h) with and without 5-O-caffeoylquinic acid (25 and 50 μM) and added to a serum or collagen I-coated plate. After washing with phosphate-buffered saline (PBS), the attached PC3 cells were fixed, stained with 5% crystal violet, and counted (A). The number of adherent cells were counted of four different areas and tabulated. PC3 cells which were treated with and without 5-caffeoylquinic acid (50 μM) were seeded on a collagen-coated plate and harvested at the indicated times. The expression of α2 integrin, β1 integrin phospho-FAK, total FAK, and GAPDH was estimated by Western blotting (B). Error bars indicate the standard deviation (SD) of the mean. Bar = 200 μm. *p < 0.05 when compared with control.